1. Field of the Invention
The present invention relates generally to electrical wiring devices, and particularly to electrical wiring devices including protective circuitry.
2. Technical Background
Electrical wiring devices often include power receptacles that may receive a corded plug to thereby supply power to electrical equipment connected to the plug. In certain environments where a greater potential for an electrical shock hazard may exist, such as in a residential bathroom or kitchen, for example, the wiring device may be equipped with a circuit protection device component, e.g., a ground fault circuit interrupter (GFCI) (however, the use of wiring devices having a circuit protection device component or capability is in no way limited to these exemplary environments). Their intended purpose is to protect the electrical power user from electrocution when hazardous ground fault faults are present. Protective devices or device components may be effective in detecting ground faults associated with damaged insulation on the line conductor that could lead to fire, or to current accidentally flowing through a human body that could cause electrocution. In general, a GFCI senses and/or responds to a condition in a line carrying electrical current, which indicates a presently or imminently dangerous condition such as the presence of a current path other than the intended path of normal operation. Response to the sensed dangerous condition maybe in the form of alarm actuation and/or opening the line (interrupting the circuit) between the source of power and the load.
Protective device components are typically provided with line terminals for coupling to the supply voltage of the electrical distribution system, and load terminals coupled to the protected portion of the system and a circuit interrupter for disconnection of the load terminals from the line terminals. The protective device may be provided with a sensor for sensing the fault, a detector for establishing if the sensed signal represents a true hazardous fault, as opposed to electrical noise, and a switch responsive to the detector sensor, wherein the circuit interrupter comprising the contacts of a relay or trip mechanism are operated by a solenoid responsive to the switch to disconnect the load terminals from the line terminals. The disconnection is also known as tripping. A power supply may be required to furnish power to the sensor, detector, switch or solenoid.
Protective device components are commonly equipped with a test button, which the owner of the protective device is instructed to operate periodically to determine the operating condition of the sensor, the detector, the switch, trip mechanism or relay, or power supply, any of which can fail and which may cause the circuit interrupter to not operate to remove power from the load side of the protective device to interrupt the fault. Since the protective device component includes both electronic and mechanical components, failure modes may result from normal aging of electronic components, corrosion of mechanical parts, poor connections, mechanical wear, mechanical or overload abuse of the protective device in the field, electrical disturbances such as from lightning, or the like. Once the test has been manually initiated by operating the test button, the outcome of the test has often been indicated mechanically such as by a popping out of a button, visually through a lamp display or pivoting flag that comes into view, or audibly through an annunciator. As an alternative to a manual test, a self-test feature can be added to the protective device for automatic testing such as is described in U.S. Pat. No. 6,421,214 and U.S. application Ser. No. 09/827,007 filed Apr. 5, 2001 entitled LOCKOUT MECHANISM FOR USE WITH GROUND AND ARC FAULT CIRCUIT INTERRUPTERS, both of which are incorporated herein by reference in their entirety. Once the test has been automatically initiated through the self-test feature, the outcome of the test can be indicated by any of the previously described methods or by the permanent disconnection of the load terminals from the line terminals of the protective device component, also known as lock-out.”
Further variations on circuit protection device components exist. For example, commonly assigned copending application Ser. No. 10/768,530, filed on Jan. 30, 2004, entitled CIRCUIT PROTECTION DEVICE WITH GROUNDED NEUTRAL HALF CYCLE SELF TEST teaches a circuit protection device that self-checks for ground fault detection every half cycle. Commonly assigned copending application Ser. No. 10/729,392, entitled PROTECTION DEVICE WITH LOCKOUT TEST teaches a device that protects from arc faults and ground faults, which is provided with a manual test feature that permanently denies power to the protected circuit should the test fail. Commonly assigned U.S. Pat. No. 6,522,510 and U.S. application Ser. No. 09/718,003 filed Nov. 21, 2000, entitled GROUND FAULT CIRCUIT INTERRUPTER WITH MISWIRE PROTECTION AND INDICATOR teaches a ground fault interrupter device with miswire protection and indicator functions. These three applications are hereby incorporated by reference in there entireties to the fullest extent allowed by applicable laws and rules.
The exemplary bathroom and kitchen environments referred to above also represent locations that occupants may visit during night time hours when these rooms are typically dark. As such, it is common to find a “night light” plugged into an electrical receptacle to provide some increased visibility in the darkness. Night light devices have various forms, styles, and designs. They all include either an on/off switch for manual operation, or a sensor that senses ambient light conditions to control the on/off state of the light. An example of a night light having a sensor is disclosed in U.S. Pat. No. 6,561,677, which is herein incorporated by reference in its entirety.
In view of the foregoing information, the applicant has become appreciative of the various economies and other advantages and benefits presented by an electrical wiring device including a circuit protection component and an auxiliary, integrated light that provides lighting and/or circuit status indication.